A blowout preventer on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in diameter, 177 feet high, and a ring pontoon 38 feet wide and 29 feet high, with a rectangular cross section. ( James Nielsen / Chronicle ) less

A blowout preventer on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular ... more

Seawater filters which are part of the water injection system on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. Water injection is used to increase the pressure inside the reservoir to increase oil recovery. ( James Nielsen / Chronicle ) less

Seawater filters which are part of the water injection system on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. ... more

Photo: Chronicle

Seawater filters which are part of the water injection system on... Photo-4589797.61875 - StamfordAdvocate

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Seawater filters which are part of the water injection system on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. Water injection is used to increase the pressure inside the reservoir to increase oil recovery. ( James Nielsen / Chronicle ) less

Seawater filters which are part of the water injection system on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. ... more

Photo: Chronicle

Seawater filters which are part of the water injection system on... Photo-4589798.61875 - StamfordAdvocate

Image 7 of 41

David Hernandez, Operations Manager for Ursa TLP
Shell Exploration & Production Company looks over some of the seawater filters which are part of the water injection system on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. Water injection is used to increase the pressure inside the reservoir to increase oil recovery. ( James Nielsen / Chronicle ) less

David Hernandez, Operations Manager for Ursa TLP
Shell Exploration & Production Company looks over some of the seawater filters which are part of the water injection system on the Shell Ursa TLP (tension leg ... more

Two of four circular steel columns which are 85 feet in diameter, 177 feet high, on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. ( James Nielsen / Chronicle ) less

Two of four circular steel columns which are 85 feet in diameter, 177 feet high, on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, ... more

Photo: Chronicle

Two of four circular steel columns which are 85 feet in diameter,... Photo-4589801.61875 - StamfordAdvocate

Image 10 of 41

One of four circular steel columns which are 85 feet in diameter, 177 feet high, on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. ( James Nielsen / Chronicle ) less

One of four circular steel columns which are 85 feet in diameter, 177 feet high, on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, ... more

Photo: Chronicle

One of four circular steel columns which are 85 feet in diameter,... Photo-4589802.61875 - StamfordAdvocate

Image 11 of 41

An access hatch in the center of one of four circular steel columns which are 85 feet in diameter, 177 feet high, on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. ( James Nielsen / Chronicle ) less

An access hatch in the center of one of four circular steel columns which are 85 feet in diameter, 177 feet high, on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf ... more

Photo: Chronicle

An access hatch in the center of one of four circular steel columns... Photo-4589803.61875 - StamfordAdvocate

Image 12 of 41

A ballast pump discharge pressure gauge inside one of the hull on the Shell Ursa TLP (tension leg platform) in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. ( James Nielsen / Chronicle )

A ballast pump discharge pressure gauge inside one of the hull on the Shell Ursa TLP (tension leg platform) in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. ( James Nielsen / Chronicle )

A door to a tunnel in approximately 98 feet underwater which connects the four circular steel columns which are 85 feet in diameter, 177 feet high, on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. ( James Nielsen / Chronicle ) less

A door to a tunnel in approximately 98 feet underwater which connects the four circular steel columns which are 85 feet in diameter, 177 feet high, on the Shell Ursa TLP (tension leg platform) located in the ... more

Photo: Chronicle

A door to a tunnel in approximately 98 feet underwater which... Photo-4589805.61875 - StamfordAdvocate

Image 14 of 41

Shell's Richard Crabtree walks in a tunnel in approximately 98 feet underwater which connects the four circular steel columns which are 85 feet in diameter, 177 feet high, on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. ( James Nielsen / Chronicle ) less

Shell's Richard Crabtree walks in a tunnel in approximately 98 feet underwater which connects the four circular steel columns which are 85 feet in diameter, 177 feet high, on the Shell Ursa TLP (tension leg ... more

Photo: Chronicle

Shell's Richard Crabtree walks in a tunnel in approximately 98... Photo-4589806.61875 - StamfordAdvocate

Image 15 of 41

Shell's Richard Crabtree walks in a tunnel in approximately 98 feet underwater which connects the four circular steel columns which are 85 feet in diameter, 177 feet high, on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. ( James Nielsen / Chronicle ) less

Shell's Richard Crabtree walks in a tunnel in approximately 98 feet underwater which connects the four circular steel columns which are 85 feet in diameter, 177 feet high, on the Shell Ursa TLP (tension leg ... more

Photo: Chronicle

Shell's Richard Crabtree walks in a tunnel in approximately 98... Photo-4589807.61875 - StamfordAdvocate

Image 16 of 41

A view looking down into one of four circular steel columns which are 85 feet in diameter, 177 feet high, on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. ( James Nielsen / Chronicle ) less

A view looking down into one of four circular steel columns which are 85 feet in diameter, 177 feet high, on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of ... more

Photo: Chronicle

A view looking down into one of four circular steel columns which... Photo-4589808.61875 - StamfordAdvocate

Image 17 of 41

The control room on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. ( James Nielsen / Chronicle )

The control room on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. ( James Nielsen / Chronicle )

The shadow of a helicopter on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in diameter, 177 feet high, and a ring pontoon 38 feet wide and 29 feet high, with a rectangular cross section.( James Nielsen / Chronicle ) less

The shadow of a helicopter on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four ... more

Photo: Chronicle

The shadow of a helicopter on the Shell Ursa TLP (tension leg... Photo-4589810.61875 - StamfordAdvocate

Image 19 of 41

One of four circular steel columns which are 85 feet in diameter, 177 feet high, on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. ( James Nielsen / Chronicle ) less

One of four circular steel columns which are 85 feet in diameter, 177 feet high, on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, ... more

Photo: Chronicle

One of four circular steel columns which are 85 feet in diameter,... Photo-4589811.61875 - StamfordAdvocate

Image 20 of 41

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in diameter, 177 feet high, and a ring pontoon 38 feet wide and 29 feet high, with a rectangular cross section.( James Nielsen / Chronicle ) less

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in ... more

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in diameter, 177 feet high, and a ring pontoon 38 feet wide and 29 feet high, with a rectangular cross section.( James Nielsen / Chronicle ) less

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in ... more

A blowout preventer on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in diameter, 177 feet high, and a ring pontoon 38 feet wide and 29 feet high, with a rectangular cross section.( James Nielsen / Chronicle ) less

A blowout preventer on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular ... more

The A-7 well on the Shell Ursa TLP (tension leg platform) which set a production of 50,150 boe (barrel of oil equivalent) in 1999, in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. ( James Nielsen / Chronicle ) less

The A-7 well on the Shell Ursa TLP (tension leg platform) which set a production of 50,150 boe (barrel of oil equivalent) in 1999, in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. ( James Nielsen / ... more

Photo: Chronicle

The A-7 well on the Shell Ursa TLP (tension leg platform) which set... Photo-4589816.61875 - StamfordAdvocate

Image 24 of 41

One of four circular steel columns which are 85 feet in diameter, 177 feet high, on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. ( James Nielsen / Chronicle ) less

One of four circular steel columns which are 85 feet in diameter, 177 feet high, on the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, ... more

Photo: Chronicle

One of four circular steel columns which are 85 feet in diameter,... Photo-4589817.61875 - StamfordAdvocate

Image 25 of 41

Workers stand in the hull of the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in diameter, 177 feet high, and a ring pontoon 38 feet wide and 29 feet high, with a rectangular cross section.( James Nielsen / Chronicle ) less

Workers stand in the hull of the Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four ... more

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in diameter, 177 feet high, and a ring pontoon 38 feet wide and 29 feet high, with a rectangular cross section.( James Nielsen / Chronicle ) less

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in ... more

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in diameter, 177 feet high, and a ring pontoon 38 feet wide and 29 feet high, with a rectangular cross section.( James Nielsen / Chronicle ) less

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in ... more

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in diameter, 177 feet high, and a ring pontoon 38 feet wide and 29 feet high, with a rectangular cross section.( James Nielsen / Chronicle ) less

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in ... more

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in diameter, 177 feet high, and a ring pontoon 38 feet wide and 29 feet high, with a rectangular cross section.( James Nielsen / Chronicle ) less

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in ... more

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in diameter, 177 feet high, and a ring pontoon 38 feet wide and 29 feet high, with a rectangular cross section.( James Nielsen / Chronicle ) less

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in ... more

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in diameter, 177 feet high, and a ring pontoon 38 feet wide and 29 feet high, with a rectangular cross section.( James Nielsen / Chronicle ) less

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in ... more

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in diameter, 177 feet high, and a ring pontoon 38 feet wide and 29 feet high, with a rectangular cross section.( James Nielsen / Chronicle ) less

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in ... more

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in diameter, 177 feet high, and a ring pontoon 38 feet wide and 29 feet high, with a rectangular cross section.( James Nielsen / Chronicle ) less

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in ... more

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in diameter, 177 feet high, and a ring pontoon 38 feet wide and 29 feet high, with a rectangular cross section.( James Nielsen / Chronicle ) less

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in ... more

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in diameter, 177 feet high, and a ring pontoon 38 feet wide and 29 feet high, with a rectangular cross section. ( James Nielsen / Chronicle ) less

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in ... more

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in diameter, 177 feet high, and a ring pontoon 38 feet wide and 29 feet high, with a rectangular cross section.( James Nielsen / Chronicle ) less

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in ... more

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in diameter, 177 feet high, and a ring pontoon 38 feet wide and 29 feet high, with a rectangular cross section.( James Nielsen / Chronicle ) less

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in ... more

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in diameter, 177 feet high, and a ring pontoon 38 feet wide and 29 feet high, with a rectangular cross section.( James Nielsen / Chronicle ) less

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in ... more

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in diameter, 177 feet high, and a ring pontoon 38 feet wide and 29 feet high, with a rectangular cross section.( James Nielsen / Chronicle ) less

The Shell Ursa TLP (tension leg platform) located in the Mississippi Canyon block 809 in Gulf of Mexico Wednesday, Oct. 17, 2012, in New Orleans. The hull is comprised of four circular steel columns, 85 feet in ... more